氧化亚氮双组元发动机热力性能计算分析

Calculation and analysis of thermodynamic performance for nitrous oxide bipropellant engine

对绿色推进剂N2O,H2,CH3OH,C2H5OH,CH4,C2H6,C2H4,C2H2,C3H8及C3H6的物性进行了全面比较,并采用吉布斯最小自由能法对9种氧化亚氮双组元推进剂组合的热力性能展开全面计算及分析。N2O/H2组合由于其最低的燃气平均摩尔质量而具有最高的比冲;N2O/C2H2组合由于C2H2很高的标准生成焓其燃烧温度可高达3823 K;碳氢燃料在余氧系数α<0.4富燃工况下燃气中含有固碳颗粒,且摩尔含量随着α的降低而急剧升高,喷管出口处可高达35%～40%;N2O/C3H8和N2O/C3H6组合拥有很好的空间应用物性和较高的热力性能,在压比pc:pe=70 atm:1 atm工况下平衡流比冲分别为2 639 m/s和2 656 m/s,具有很好的应用前景。

The physical properties of green propellants N2O, H2, CH3OH, C2H5OH, CH4, C2H6, C2H4, C2H2, C3H8 and C3H6 were compared. The thermodynamic performance of nine nitrous oxide bipropellants were calculated and analyzed completely with the minimum free energy method. N2O/H2 has the best specific impulse because of the lowest combustion gas average molar mass. N2O/C2H2 possesses the highest adiabatic combustion temperature which can reach 3 823 K owing to the high standard formation enthalpy of C2H2. The combustion gas of hydrocarbon fuel bipropellant contains carbon particles while its excess-oxidizer coefficient a〈0.4, and the carbon content which can reach 35% 40% at nozzle exit increases sharply with the a decrease. The theoretical equilibrium specific impulse of N20/C3H8 and N20/C3H6 under work condition of pc ： pe=70 arm： latm are 2 639 m/s and 2 656 m/s, and these two. bipropellants possess attractive space application properties and highly ther-modynamic performance.